TEZ-1116. Refactor YarnTezDAGChild to be testable and usable for
LocalMode. (sseth)
TEZ-1143 (addendum). 1-1 source split event should be handled in Vertex.RUNNING and Vertex.INITED state (bikas)
TEZ-1145. Vertices should not start if they have uninitialized custom edges (bikas)
TEZ-1159. Fix handling of corrupt or empty files in recovery data. (hitesh)